Mammary Gland Growth in the Hypophysectomized Pregnant Rat 1 2
Mammary Gland Growth in the Hypophysectomized Pregnant Rat 1 2
复制标题
垂体切除妊娠大鼠的乳腺生长 1 2
DOI：
10.3181/00379727-148-38522
复制
发表时间：
1975
影响因子：
--
通讯作者：
Ralph R. Anderson
中科院分区：
文献类型：
--
作者：
Ralph R. Anderson
在妊娠第11、12或15天切除Sprague-Dawley-Rolfsmeyer大鼠的垂体，并在第20天处死，以确定乳腺发育的程度，通过测定核酸含量进行评估。6个腹腹股沟腺的DNA在垂体切除组中与假手术妊娠组或完整妊娠对照组无显著差异。各妊娠组乳腺DNA含量均显著高于处女对照组和去垂体流产组。为了确定维持妊娠和乳腺生长所需的最小胎盘-胎仔单位数量，除垂体外，在妊娠第12天取出胎仔和胎盘，以便在一组6只大鼠的子宫中仅保留一只胎仔和一个胎盘，其他组保留2、3、4或5只。妊娠维持只有一个胎盘胎儿单位，但乳腺增生显着低于对照组在妊娠第20天。三至五个概念，tuses支持乳腺增生在后半期妊娠的水平没有显着不同的完整或假手术对照组。在第12天切除垂体完整的大鼠的胎盘单位，当保留1-5个单位时，乳腺DNA无变化。在第12天去除垂体和在第14天去除胎盘-胎儿单位也导致乳房DNA没有变化，只有两个胎盘（减去所有胎儿），而仅保留一个胎盘导致乳房DNA显著低于具有2个或更多胎盘的组。
Summary Sprague-Dawley-Rolfsmeyer rats were hypophysectomized on days 11, 12 or 15 of pregnancy and sacrificed on day 20 to determine the extent of mammary development, as assessed by determination of nucleic acid content. The DNA of six abdominalinguinal glands in the hypophysectomized groups was not significantly different from that in the sham-operated pregnant or intact pregnant control groups. All groups maintaining pregnancy had significantly higher DNA contents in mammary glands than virgin control or hypophysectomized-aborted groups. In order to determine the minimal numbers of placental-fetal units required to maintain pregnancy and mammary gland growth, fetuses and placentas were removed on day 12 of pregnancy in addition to the pituitary so that only one fetus and one placenta remained in the uterus of a group of 6 rats with other groups having 2, 3, 4 or 5 remaining. Pregnancy was maintained with only one placental-fetal unit, but mammary gland proliferation was significantly lower than the control group on day 20 of pregnancy. Three to five concep-tuses supported mammary proliferation during the latter half of pregnancy at a level not significantly different from intact or sham-operated control groups. Removal of pla-cental units on day 12 in rats having pitui-taries intact resulted in no mammary DNA change when 1-5 units remained. Removal of pituitaries on day 12 and placental-fetal units on day 14 also resulted in no change in mammary DNA with as little as two placentas (minus all fetuses), while only one placenta remaining resulted in a significantly lower mammary DNA than in groups with 2 or more placentas.